A vinyl halide is clearly a species with a formula H_2C=C(X)H, in which a halide is directly bound to an olefinic bond. Formally, this is ethylene, H_2C=CH_2, with one of the hydrogens substituted by a heteroatom. Vinyl chloride, H_2C=CHCl is an example. An aryl halide has general formula C_6H_5X, in which an halide group X has substituted the aryl ring. The simplest examples of an aryl halides are bromobenzene or chlorobenzene, C_6H_5X.
Of course, we often represent benzene with a formula of "1,3,5-cyclohexatriene", but this is a representation rather than an actuality. In an aromatic ring, the pi electrons are conceived to be delocalized around the ring.
